Mechanical forces cause changes in form during embryogenesis and likely play a role in regulating these changes. This paper explores the idea that changes in homeostatic tissue stress (target stress), possibly modulated by genes, drive some morphogenetic processes. Computational models are presented to illustrate how regional variations in target stress can cause a range of complex behaviors in...

We investigated the use of mechanical stress to bend carbon-carbon triple bonds. Formation of an isoquinoline after reaction with a benzyl azide trap points towards a nucleophilic addition mechanism, differentiating mechanochemical trans-bending of π bonds from the typical reactivity observed for cisoidal bending of triple bonds in strained cyclic alkynes.

versus ethylene oxide (ETO) sterilization on the mechanical strength of cortical bone grafts. Tibias were collected from cadavers of mature goats. Sixty test specimens were randomized into four groups : fresh (no processing), frozen (freezing at –70°C), gamma-irradiated, and ETO-sterilized specimens. Torsion, three-point bending, and compression testing were separately performed with a material...

The mechanical behavior of an ensemble of athermal fibers forming a nonbonded network subjected to triaxial compression is studied using a numerical model. The response exhibits a power law dependence of stress on the dilatation strain and hysteresis upon loading and unloading. A stable hysteresis loop results after the first loading and unloading cycle. In the early stages of compaction, strai...

To date, transverse and vertical forces applied eccentrically to the axis of dental implants in the molar area during oral function have not been quantified. A specially designed load cell placed directly in the implant allowed for measurements of bending moments. Results of both load directions were compared to each other and to the loads applied vertically along the implant axis. The stress i...

The mechanical behavior of cold rolled sheets is significantly related to residual stresses that arise from bending and unbending processes. Measurement of residual stresses is mostly limited to surface measurement techniques. Experimental determination of stress variation through thickness is difficult and time-consuming. This paper presents a closed form solution for residual stresses, in whi...

tehran shomal highway passes through alborz mountains with a tunnel length of 6400 meters. there are two main tunnels. a full three-dimensional (3d) numerical analysis coupled with elasto-plastic material models was conducted on the inclined access tunnel. bending moment, axial force and the lining displacements due to the internal forces applied on the shotcrete lining are calculated. axial fo...

An elastic analysis is presented for the tensile stretching and bending of a plate containing a surface crack penetrating part-through the thickness, Fig. 1. The treatment is approximate, in that the two-dimensional generalized plane stress and KirchhoffPoisson plate bending theories are employed, with the part-through cracked section represented as a continuous line spring. The spring has both...

This study reviews world literature on the strength-related effect of duration and rate of loading on wood and wood-based materials. Also, early developments are discussed which led to the currently used permanent loading factor of 9/16. Published data on duration of load are reanalyzed and compared. The comparisons suggest that the effect of stress level on duration of stress for wood is great...